NC0003425_Correspondence_20191022

V f DUKE
ENERGY,
PROGRESS
File: 12520
Mr. Rick Bolich
North Carolina Division of Environmental Quality
1628 Mail Service Center
Raleigh, NC 27699-1628
Subject: Roxboro Electric Generating Plant
NPDES Permit No.00003425
Five-day Follow-up Letter
Incident No.272096
Dear Mr. Bolich:
Duke Energy Progress, LLC
Roxboro Steam Electric Plant
1700 Aun nan ur Road
Seinora NC 27.44
October 22, 2019
NC Dept of Environmental Quality
OCT 18 2019
Raleigh Regional Office
On October 20, 2019 at approximately 1:23 F.M., Duke Energy staff made verbal notification to Mr.
George Bernard of an unanticipated bypass of treatment at the Roxboro Steam Station in Person County.
The verbal notification was made as required by Fart II, Section E.9.(c) of the above -referenced permit.
Also, as required by Part Il, Section E.9, this letter fulfills the five-day written letter requirement.
At approximately 7:32 A.M. on Sunday, October 20, 2019, station operations received a Hi level alarm in
the process water redirect sump during a period of intense rain. Station operations verified from DCS that
two available normal service pumps (pumps B & C) were in service and operating when the Hi Hi level
alarm was received approximately two minutes after the first alarm. A station operator was dispatched to
investigate. While in route, another alarm for Lined Retention Basin inlet valve deviation was received,
indicating low flow for the B & C pumps and tripping both off. The station operator and supervisor
arrived at the sump to find the level elevated and overflowing into the heated water discharge canal. A
higher capacity secondary Lined Retention Basin inlet valve failed to open on the Hi Hi level alarm which
also had signaled and caused the primary valve to close. The primary inlet valve was forced open from
the DCS allowing flow from the B & C pumps to be restored. Concurrently, the operator and supervisor
placed the standby diesel pump in service.
The process water redirect sump level decreased below overflow within 4 minutes. Total estimated
overflow time was 10 minutes according to DCS alarm history. The primary inlet valve will remain in
manual to prevent loss of flow until the secondary valve can be repaired.
The total bypass volume discharged to heated water discharge canal was estimated to be 3,500 gallons.
Duke Energy made an environmental event press release on October 20, 2019 and included it on the Duke
Energy website.
If you have any questions concerning this ;ubmittal, please contact Ms. Lori Tollie at (336)-8544916 or
at [e-mail].
"I certify, under penalt-Y of la►r, that this doctuuent and till attachments n-ere prepared tinder ruy
direction or supert-ision in accordance iiith a system designed to assure that qualified personnel
properly gather and evahutte the information submitted. Based on mY inquiry of the person or

DUKE
ENERGY.
PROGRESS
Duke Enerl;y Progress, LLC
Rnxbora Steam Elecuie Plant
1700 Dunncnt'av Road
Sonora, NC 2744.4
persons who manage the system, or those persons elirectlS• responsible for gathering the
information, the information submitted is, to the best of nn knowledge and belief, trite, accurate,
and complete. 1 cam aware that there are significant penalties for submitting false information,
including the pos•s•ibilit►, of fines and imprisonment for knowing violations. "
Sincerely,
Tom Copolo
General Manger — Roxboro Steam Station